Designing TiO2 nanostructures through hydrothermal growth: influence of process parameters and substrate position

Synthesis conditions and processing parameters profoundly affect the growth and morphology of nanostructures. In particular, when nanostructures are fabricated through a chemical technique such as hydrothermal, the process parameters such as reaction time, temperature, precursor concentration, and substrate orientation play a crucial role in determining the structure-property relationships. In this work, we report the hydrothermal growth of Titanium dioxide (TiO2) nanostructures as a function of these parameters and show that specific morphologies can be obtained by a variation of these parameters. A systematic study is carried out to understand the influence of reaction time (from 0.5 h to 3.0 h), reaction temperature (180 degrees C-200 degrees C), titanium precursor concentration (0.25 ml and 0.50 ml in 20 ml solution of HCl and deionized water) and substrate orientation (horizontal and tilted at an angle), and we show that significant variation in morphology- from nanowires to nanorods and then dandelions can be achieved. In particular, we demonstrate that high surface area multidirectional growth of nanorods leading to flower-like nanostructures or dandelions resulting from precipitation during the hydrothermal process. This is in contrast with previous reports on similar structures, where the role of precipitations was not analyzed. The work shows a possibility to control such growth by manipulating substrate position inside the autoclave during the hydrothermal process and will be useful for surface-dependent applications.

Automated summary

Synthesis conditions and processing parameters significantly influence the growth and morphology of nanostructures, allowing for control over their shapes. This study demonstrates the hydrothermal growth of TiO2 nanostructures and shows that varying parameters like reaction time, temperature, precursor concentration, and substrate orientation can lead to different morphologies such as nanowires, nanorods, and dandelions. Manipulating the substrate position inside the autoclave during the hydrothermal process offers a possibility to control the growth of nanostructures, which may have implications for surface-dependent applications.